In the Trenches,Cost Containment Ain't Always Easy: An Illustrative Case Report

A specific case report illustrates the interplay between human considerations and technological potency that makes cost containment difficult in the real world of medical practice.     

Androecial Development in Six Polyandrous Genera Representing Five Major Groups of Palms

Floral organogensis is described for six polyandrous generarepresenting borassoid, caryotoid, ceroxyloid, inarteoid, andgeonomoid major groups of palms. In all, three sepals and threepetals arise from dome-shaped floral apices in alternate pseudo-whorls.After petal inception, the floral apex expands in a differentway in each major group. Different numbers and arrangementsof stamens develop in antesepalous (AS) and antepetalous (AP)positions Primary pnmordia are sometimes distinct, and stamenpnmordia vary in form In borassoid and caryotoid palms, AS whorlsalways consist of three stamens, but several stamens arise inthe lower, wider AP positions Ceroxylon is characterized bylarge primary primordia with two to three stamens developingopposite each petal and, in species with more than 12 stamens,two to three also opposite each sepal. Several stamens ariseon distinctive truncate, AS primordia in a definite patternthat is repeated in AP positions in inarteoid palms In polyandrousgeonomoid genera, stamens arise in AS and AP arcs on a flattrilobed floral apex. Previous work has shown similarities instamen inception in arecoid genera to that in borassoid andcaryotoid palms, and centrifugal initiation in all phytelephantoidpalms. All polyandrous taxa, except phytelephantoid palms, exhibita basic tnmery. The different patterns of apical expansion andstamen arrangement indicate that polyandry has arisen separatelyin each major group of palms. The mode of apical expansion andthe form of the primordia appear to depend on pressures imposedon the floral apices, suggesting that specialization of inflorescencebracts and perianth segments preceded the evolution of polyandry.Correlations of vasculature with developmental patterns areindicated. Lodoicea maldivica (Gmelin) Persoon, Caryota mitis Loureiro, Ceroxylon alpinum Bonpland ex DeCandolle, Socratea exorrhiza (Martius) H. Wendland, Wettima castanea Moore and Dransfield, Welfia georgii H. Wendland ex Burret, palms, androecium, stamen development     

Antibodies Blocking the Mating Reaction In Paramecium Multimicronucleatum Syngen 2

SYNOPSIS Antibodies induced in rabbits against Paramecium multimicronucleatum syngen 2 prevent sexually reactive cells from clumping, pairing, and forming cytoplasmic fusions. A biologic assay for the detection of these antibodies (designated blocking antibodies ) is described. the blocking antibodies, unlike the immobilization antibodies, are produced against breis of sexually reactive cells and nonreactive cells of 2 types, nonstarved and immature. Isolated cilia from reactive cells of either mating type are weak immunogens for blocking antibodies. No correlation between the mating type specificity (III or IV) and these antibodies has been detected. Blocking antibodies can be absorbed with living cells, of which sexually reactive ones are the most effective absorbers, while immature ones are the least effective.     

Deuterostome phylogeny and the sister group of the chordates: evidence from molecules and morphology

Complete coding regions of the 18S rRNA gene of an enteropneust hemichordate and an echinoid and ophiuroid echinoderm were obtained and aligned with 18S rRNA gene sequences of all major chordate clades and four outgroups. Gene sequences were analyzed to test morphological character phylogenies and to assess the strength of the signal. Maximum- parsimony analysis of the sequences fails to support a monophyletic Chordata; the urochordates form the sister taxon to the hemichordates, and together this clade plus the echinoderms forms the sister taxon to the cephalochordates plus craniates. Decay, bootstrap, and tree-length distribution analyses suggest that the signal for inference of dueterostome phylogeny is weak in this molecule. Parsimony analysis of morphological plus molecular characters supports both monophyly of echinoderms plus enteropneust hemichordates and a sister group relationship of this clade to chordates. Evolutionary parsimony does not support chordate monophyly. Neighbor-joining, Fitch-Margoliash, and maximum-likelihood analyses support a chordate lineage that is the sister group to an echinoderm-plus-hemichordate lineage. The results illustrate both the limitations of the 18S rRNA molecule alone for high- level phylogeny inference and the importance of considering both molecular and morphological data in phylogeny reconstruction.      

Terbutol Affects Spindle Microtubule Organizing Centres

Light, immunofluorescence, and electron microscopy were utilizedto investigate the effects of the herbicide terbutol (2,6-di-tert-butyl-p-tolylmethylcarbamate) on onion root tips. So-called ‘star anaphases,’chromosomes drawn in at their centromeres at both poles, resultingin a starburst of chromosomes were the predominant form of mitoticabnormality noted in root tip squashes of the terbutol-treatedroots. Immunofluorescence microscopy using antitubulin serareveals a cluster of microtubules radiating from the centreof the chromosome mass at each of the poles. Nuclear envelopesapparently reform around the radially-arranged chromosome masses,resulting in extensively lobed ‘star telophase’nuclei. Branched and curved phragmoplast arrays are observed,due to interference by the lobes of the star telophase nucleus.These abnormal phragmoplasts result in incomplete and/or abnormally-orientedcell walls. Star anaphase figures are observed after 2 h ofherbicide treatment, indicating that this terbutolinduced chromosomalabnormality is a primary effect of the herbicide. Tradescantiastamen hairs were treated with terbutol and mitosis was monitoredin vivo by Nomarski differential interference microscopy; thesetreated stamen hairs produce star anaphase figures as a primaryeffect of the herbicide. This series of abnormalities has notbeen observed with any other herbicide, indicating that terbutolhas a unique mechanism of action, perhaps interacting with spindlemicrotubule organizing centres. Key words: Terbutol, Onion, root tips, star-anaphase figures